<% Daru::IRuby::Helpers.tuples_with_rowspans(@index).first(threshold).zip(to_a).each do |tuple, value| %>
<% tuple.each do |idx, span| %>
<%= idx %> |
<% end %>
<%= value %> |
<% end %>
<% if size > threshold %>
<% last_index = @index.to_a.last %>
<% last_index.size.times do %>
... |
<% end %>
... |
<% last_index.each do |idx| %>
<%= idx %>
<% end %>
| <%= self[last_index] %> |
<% end %>